DVR2-D™ Dynastart Regulator

(DVR4 Neg 12V/8A can be used as alternative)

electronic dynamo regulator & cut-out: current limited, field to live ('series')



Plus UK, European or Rest of World postage RoW includes Australasia, Americas, Africa & India!

Please select the correct postage amount Select the price including postage to your address from the box below. Use the drop down arrow '∨' to the right to show your options

Region & Postal Service


Description and features of the DVR2-D™

The DVR2-D™ regulator suits 2, 3 & 4 wheelers (and some watercraft etc.) fitted with Dynastart units, e.g. Berkeley, Heinkel, Messerschmitt & Isetta microcars and certain Villiers powered motorcycles. It is sized to fit inside both Siba and Bosch control units, after the original regulator and cutout bobbins (and field resistor) have been removed. The starter solenoid bobbin should be left in place.

Available for Negative Earth connection only.

Where original appearance is not required a DVR4 regulator/cut-out may be used instead of the DVR2-D, with a separate solenoid. Also use a DVR4 for 6V Dynastarts, or where 11 Amp current limit is required. This option may be easier to install and the electrical performance will be the same.

The DVR2-D unit ('D' for Dynastart) is the latest version of what we called the DVR2-S ('S' for Series field connection). The generator has one end of field winding connected to 'live' armature output, as opposed to the earthed field of standard Lucas ('shunt') dc generators. Now bubblecars fitted with Dynastarts tend to have a lights-on electrical load very close to the maximum rating of the charging section. This leaves little room for error before overloading the dynamo and failure. So overload protection in the form of precise current limiting is incorporated in this electronic controller as an essential feature. Eight Amps continuous is available, amounting to 110 Watts, but above this the regulated voltage is reduced so that output is restricted to an absolute maximum of 9 Amps. The DVR2-D™ is a 12 V negative earth unit. It is supplied with a data-sheet including fitting advice.

Body size is 38mm x 38mm x 25mm. Connections are by flying leads of approximately 120 mm. Bared wire ends allow the customer to connect using their preferred method.

The DVR2-D™ promotes better lights & properly charged batteries

The field winding resistance must be greater than 2.5 ohms.

DVR2-D™ Specification

  • 12 Volt
  • Negative earth
  • Size - 38mm x 38mm x 25mm
  • Fits in Siba or Bosch cases
  • Or mount on its own with single M5 screw
  • Fitted with 1 mm sq leads with continental colour coding
  • Use with Siba or Bosch Dynastarts and other 'series field' wired dynamos
  • The DVR2-D™ is potted in an aluminium case for robustness & excellent heat transfer

Battery voltage is stable (above cut in speed) regardless of your speed

Robust & reliable, cool running & efficient. More light, Less heat.

View DVR2-D™ data sheet (Adobe Acrobat PDF format)


We also stock a small range of useful accessories to accompany your new Regulator!

The DVR2™ may be similar in cost to some other regulators but its performance and reliability is superior to these competitors. With the DVR2™, there is no battery discharge to field at low revs. Battery voltage is stable (above cut in speed) regardless of your speed. Dynamo will start up (and be regulated!) with no or very low battery.

View our range of Voltage Regulators